超长大体积混凝土施工中的裂缝控制

Cracking Control for Super-long Mass Concrete in Construction

以上海世茂深坑酒店超长大体积混凝土基础梁工程为例,采用"跳仓法"综合技术对温度裂缝进行控制。同时通过对混凝土内部各点温度的实时监测,分析施工过程中温度场的变化情况。工程结果表明,在混凝土浇筑后的14d内,中心温度起伏较大,并且在第4天达到最大值;当混凝土内部降温速率高于规范要求时,通过"跳仓法"以及增配温度筋、减少基底约束等措施有效控制裂缝的产生。

To restrain the crack induced by cement hydration heat,the alternative construction method and comprehensive technique measures were adopted for super long foundation beam in Shanghai Shimao Chasm Hotel. Also,changes of temperature field of concrete were analyzed with real-time monitoring.Engineering results showed that concrete core temperature varing greatly in 14 days after casting reached the maximum in the fourth day,cracks could be controlled effectively by alternative construction method,adding temperature steel bars and reducing basal constraint,when falling temperature of concrete exceeds the code requirement.